4 Presidential Address 



perturbing period in which we live. 

 Different persons would give different 

 answers, but the answer I venture to give 

 is Rapid progress, combined with Fun- 

 damental scepticism. 



Rapid progress was not characteristic 

 of the latter half of the nineteenth 

 century, at least not in physics. Fine 

 solid dynamical foundations were laid, 

 and the edifice of knowledge was con- 

 solidated; but wholly fresh ground was 

 not being opened up, and totally new 

 buildings were not expected. 



In many cases the student was led to believe 

 that the main facts of nature were all known, 

 that the chances of any great discovery being 

 made by experiment were vanishingly small, and 

 that therefore the experimentalist's work con- 

 sisted in deciding between rival theories, or in 

 finding some small residual effect, which might 

 add a more or less important detail to the 

 theory. Schuster. 



With the realisation of predicted ether 

 waves in 1888, the discovery of X-rays in 

 1895, spontaneous radioactivity in 1896, 



